Chemistry Commons^™

Spectroscopic Study Of Uranium (Vi) Reduction By Plant Biomass, Margaret C. Murphy, John Bargar, Noémie Janot

STAR Program Research Presentations

Uranium is a common and problematic groundwater contaminant at Department of Energy legacy sites. At the former uranium ore processing plant at Rifle, Colorado, sediments rich in decayed plant biomass contain large concentrations of uranium that are slowly being released back to the aquifer. To simulate the reaction that occurs in organic rich sediments of the Rifle aquifer, biomass was incubated in U (VI) bearing groundwater. Carbon X-ray absorption spectroscopy (XAS) was then used to measure if uranium was bound to the biomass. When uranium binds to biomass the peaks in the C XAS spectra will change shape. Uranium L …

Foundational Concepts And Underlying Theories For Majors In "Biochemistry And Molecular Biology", John Tansey

Chemistry Faculty Scholarship

Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members and science educators from around the country that focused on identifying: 1) core principles of biochemistry and molecular biology, 2) essential concepts and underlying theories from physics, chemistry, and mathematics, and 3) foundational skills that undergraduate majors in biochemistry and molecular biology must understand to complete their major coursework. Using information gained from these workshops, as well as from the ASBMB accreditation working group and the NSF Vision and Change report, the Core Concepts working group has developed a consensus …

Development Of Colloid Displacement Lithography Platforms For Sensor Applications, Mahesh Thugu

Masters Theses & Specialist Projects

In this work, Poly (diallyldimethylammonium) chloride - (PDDA) was used as a base layer for developing colloid displacement lithography platforms for sensor applications. Previous work shows that glass coated with PDDA and exposed to gold acts as a good platform for colloid displacement lithography. However, for actual sensor applications, electrical isolation of individual sensor sections must be achieved. This is attempted by laying down a 40 μm stripe of PDDA on a cleaned substrate and coating that stripe with gold colloid. The size of 40 μm or less in width is set as the target to fit within the scan …

Single Step Synthesis Of Antibiotic Kanamycin Embedded Gold Nanoparticles For Efficient Antibacterial Activity, Shravan Gavva

Masters Theses & Specialist Projects

Nanotechnology has become the most advanced type of drug delivery system within the last decade. This advancement shifted the focus on small carriers to increase the efficiency of the drugs. Among these, gold nanoparticles (GNPs) were found to have profound biomedical applications. In current research, kanamycin embedded GNPs were prepared in a single step, single phase, and bio-friendly (green synthesis) procedure. The synthesized Kanamycin-GNPs (Kan-GNPs) were spherical in shape and had a size range of 15 ± 3 nm. The chosen kanamycin is an aminoglycosidic antibiotic that is isolated from Streptomyces kanamyceticus. These special antibiotic GNPs are further characterized using …

Effects Of Xanthan/Locust Bean Gum Mixtures On The Physicochemical Properties And Oxidative Stability Of Whey Protein Stabilized Oil-In-Water Emulsions, Goutham Puli

Masters Theses & Specialist Projects

Scientific evidence shows that dietary intake of the omega-3 polyunsaturated fatty acids is beneficial to human health. Fish oil is a rich source of omega-3 fatty acids. However, fish oil with high levels of omega-3 PUFA is very susceptible to oxidative deterioration during storage. The objective of this study was to investigate the effect of xanthan gum (XG)-locust bean gum (LBG) mixtures on the physicochemical properties of whey protein isolate (WPI) stabilized oil-in-water (O/W) emulsions containing 20% v/v menhaden oil. The O/W emulsions containing XG/LBG mixtures were compared to emulsions with either XG or LBG alone. The emulsions were prepared …

Reinventing Aromatic Substitution: A Novel Look, Quang Nguyen

Masters Theses & Specialist Projects

Electrophilic aromatic substitution (EAS) and directed ortho-metalation (DoM) involve the direct substitution of an arene hydrogen. A major drawback involving EAS is the necessity for harsh forcing conditions for the reaction to proceed. Catalysts such as Lewis acids FeBr₃ and AICI₃ for the introduction of halogens and acyl groups, respectively, are each highly toxic and corrosive. Textbook preparations of aryl iodides classicaly involved the use of iodine and nitric acid. This approach affords only modest yields and does not provide regiospecific substitution of most substituted aromatics because most contain ortho/para directors which afford mixtures of …

Analysis Of Kyrock For Leaching Of Impurities In Synthetic Rainwater, Santhosh Kumar Kasulavada

Masters Theses & Specialist Projects

Kyrock is a coarse grained sandstone with a complex mixture of organic and inorganic compounds. Mining of Kyrock is for use in road construction and roofing. Kyrock samples were analyzed using scanning electron microscopy to obtain elemental analysis. High levels of carbon indicate the presence of organic compounds. Analysis of an acid digestion of the samples using inductively coupled plasma spectroscopy showed inorganic compounds such as titanium oxide, vanadium oxide along with traces of arsenic. Elemental analysis of samples indicates a percent of carbon, and sulfur with no notable traces of nitrogen. Pyrolysis of the samples was done using gas …

Selective Catalytic Oxidation Of Organic Sulfides By Iron (Iii) Porphryin Catalysts And Generation Of Iron (Iv)-Oxo Prophyrin Radical Cations, Nawras A. Asiri

Masters Theses & Specialist Projects

Macrocyclic ligand-complexed transition metal-oxo intermediates are the active oxidizing species in a variety of important biological and catalytic oxidation reactions. Many transition metal catalysts have been designed to mimic the predominant oxidation catalysts in nature, namely the cytochrome P450 enzymes. Iron porphyrin complexes have been the center of research as catalysts. In this study 5,10,15,20- tetramesitylporphyrin (H₂TMP) and its corresponding iron complexes Fe^III(X)TMP (X= Cl, ClO₄, ClO₃, NO₃, NO₂, and BrO₃) have been successfully synthesized and fully characterized by UV-vis and NMR spectroscopies. For the catalytic …

Synthesis And Computational Studies Of A New Class Of Lanthanide Niobate Cluster : [Ln4(H2O)8(So4)5(Nbo3)2]+3h2O; Ln= Dy, Tb, Brady D. Garabato

Masters Theses & Specialist Projects

Polyoxoniobates (PONbs) are a small family of highly electron-rich clusters. The development of new solids composed of these clusters have applications in green energy and electronics. However, the high charge environment of PONbs typically requires alkaline synthetic conditions that are unsuitable for introducing other metals and organic molecules, making synthesis of new systems difficult. To date, very few transition metals and organic ligands have been incorporated into these PONb solids, and lanthanide metal inclusion, which generally improves photoconductivity due to longlived f-orbital excitations, has not yet been fully realized. Here, the synthesis of a new class of lanthanide niobate cluster …

Ionic Conductivity In Non-Ionic Compounds, Usha Kranthi Avala

Masters Theses & Specialist Projects

The main objective of this work is to investigate the ionic conductivity of the drugs under certain conditions and also to compare the ionic conductivities of drugs determined by single surface sensors and parallel plate sensors. The ionic conductivity of various materials at their pre-melt and melt states are studied in order to further study a recently discovered phenomenon. Polar solids like Lidocaine, Ketoconazole, Procainamide and Nifedipine were examined in this study. Experimental studies show an increase in ionic conductivity in both pre-melt (20 -30 °C below melting temperature) and melt transition regions. Results of ionic conductivity of both parallel …

Cross-Species Malaria Immunity Induced By Chemically Attenuated Parasites, Michael F. Good, Jennifer M. Reiman, I. Bibiana Rodriguez, Koichi Ito, Stephanie K. Yanow, Ibrahim M. El-Deeb, Michael R. Batzloff, Danielle I. Stanisic, Christian Engwerda, Terry Spithill, Stephen L. Hoffman, Moses Lee, Virginia Mcphun

Faculty Publications

Vaccine development for the blood stages of malaria has focused on the induction of antibodies to parasite surface antigens, most of which are highly polymorphic. An alternate strategy has evolved from observations that low-density infections can induce antibody-independent immunity to different strains. To test this strategy, we treated parasitized red blood cells from the rodent parasite Plasmodium chabaudi with secocyclopropyl pyrrolo indole analogs. These drugs irreversibly alkylate parasite DNA, blocking their ability to replicate. After administration in mice, DNA from the vaccine could be detected in the blood for over 110 days and a single vaccination induced profound immunity to …

Thermal And Photochemical Reactions Of Large Metallaborane Clusters And Functionalizations Of Boron Nitride Nanosheets, Pei Ma

Dissertations - ALL

The thermal and photochemical pathways of several metallaborane compounds and the functionalization of boron nitride nanosheets have been investigated. The nanosheets have potential applications in Dye Sensitized Solar Cells.Chapters 1 and 3 describe the thermal and photochemical pathways for two metalladecaboranes, [nido -6-Mn(CO) ₃ B ₉ H ₁₃ ][NMe ₄ ] (1.1) and [6-C₅Me₅-nido-6-RhB₉H₁₃] (3.1). Isomerization or cage closure reactions were observed depending on the reaction conditions and the transition metal employed. Characterized products include the firstnido-5 metalladecaborane and ahypercloso-metalladecaborane containing a group 7 transitional metal, compound1.3 and1.4, respectively. Other findings include …

Controlled Formation Of Emissive Silver Nanoclusters Using Rationally Designed Metal-Binding Proteins, Vasily A. Morozov, Michael Y. Ogawa

Chemistry Faculty Publications

The metal-binding properties of rationally designed, synthetic proteins were used to prepare a series of emissive silver nanoclusters having predictable sizes and emission energies. Metal-binding a-helical coiled coils were designed to exist as peptide trimers, tetramers, and hexamers and found to uniquely bind 6, 8, and 12 Ag+ ions, respectively. Subsequent treatment with a chemical reducing agent produced a series of peptide-bound Ag-0 nanoclusters that display a strong visible fluorescence whose emission energies depend on the number of bound metal ions in excellent agreement with theory.

In Situ Quenching And Post-Polymerization Modification Of Telechelic Polyisobutylene, Todd Raymond Hartlage

Dissertations

Polyisobutylene (PIB) is a saturated hydrocarbon elastomer that can only be produced by cationic polymerization. The water-initiated, chain transfer controlled synthesis conducted on an industrial scale produces monofunctional PIB with mixed olefin end groups. Living cationic techniques produce mono- and di-functional telechelic PIB. In situ quenching is the process of adding functional molecules to the polymerization reactor after all monomer is consumed. These quencher species bond to the chain ends, installing their latent functionality onto the polymer chain. To date, all quenchers utilized have been soft π-nucleophiles.

In the first project, free thiols, both aromatic and aliphatic, are shown to …

X-Ray Crystal Structures Of: [Rh2(N-{2,4,6-Ch3}C6h2)Coch3)4]•2ncc6h4 And Ba1.5[Fe(C10h13n2o7)][Co(Cn)6]•9h2o; Two Crystallographic Challenges, Kenneth K. Kpogo

Electronic Theses and Dissertations

The novel compound, [Rh₂(N-{2,4,6-CH₃}C₆H₂)COCH₃)₄] was synthesized. Crystal structures of [Rh₂(N-{2,4,6-CH₃}C₆H₂)COCH₃)₄]·2NCC₆H₅ and Ba_1.5[Fe(C₁₀H₁₃N₂O₇)][Co(CN)₆]·9H₂O were determined employing a Rigaku Mercury375R/M CCD (XtaLAB mini) diffractometer with graphite monochromated Mo-Kα radiation. For [Rh₂(N-{2,4,6-CH₃}C₆H₂)COCH₃)₄]·2NCC₆H₅, the space group was P-421c(#114) with unit cell dimensions: a =11.0169(14)Å, c =21.499(3)Å, V …

Fabrication Of Tungsten Tips Suitable For Scanning Probe Microscopy By Electrochemical Etching Methods, Gobind Basnet

Graduate Theses and Dissertations

The fabrication of metal tips is becoming an interesting field for scientists who are working in spectroscopy measurements. A significant amount of work has already been done in the tips fabrication process. Metal tips used to analyze the surface of materials play a key role in the scanning tunneling microscope (STM) technique. It's remarkable quality that it is used to study the surface of material at the atomic level.

There are various methods used in the tips fabrication process. Of diverse methods, three different electrochemical etching methods: submerged method, single lamella drop-off method, and double lamella drop-off method are commonly …

The Magnesium Isotopologues Of Mgh In The A2Π-X 2Σ+ System, Kenneth H. Hinkle, Lloyd Wallace, Ram S. Ram, Peter F. Bernath, Christopher Sneden, Sara Lucatello

Chemistry & Biochemistry Faculty Publications

Using laboratory hollow cathode spectra we have identified lines of the less common magnesium isotopologues of MgH, ²⁵MgH and ²⁶MgH, in the A²Π-X²Σ⁺ system. Based on the previous analysis of ²⁴MgH, molecular lines have been measured and molecular constants derived for ²⁵MgH and ²⁶MgH. Term values and linelists, in both wavenumber and wavelength units, are presented. The A²Π-X²Σ⁺ system of MgH is important for measuring the magnesium isotope ratios in stars. Examples of analysis using the new linelists to derive the Mg isotope ratio in …

Biophysical Understanding Of Novel Synthetic Amyloid-Β (Aβ) Prions In Alzheimer's Disease, Amit Kumar

Dissertations

Oligomers of amyloid-β (Aβ) peptide are the primary toxic agents that play a pivotal role in the pathogenesis of Alzheimer’s disease (AD). Oligomers are the intermediates formed during the Aβ aggregation process leading up to insoluble fibrils. It is important to know that oligomers can also be formed via pathways that do not lead to fibril formation. Such ‘off-pathway’ oligomers would have significantly longer half-lives than the ‘on-pathway’ ones, which may result in prolonged toxicity to neuronal cells. Furthermore, neither the mechanism of neurotoxicity nor the potential mechanisms of propagation and proliferation to neighboring cells are well understood. Moreover, recent …

Relation Between The Adsorption Behavior And Bulk Complexation In Oppositely Charged Polyelectrolyte-Surfactant Systems: Effect Of Polyelectrolyte Concentration, Molecular Weight, Charge Localization And Backbone Rigidity/Hydrophobicity, Vipul Suhas Padman

Dissertations

Due to a wide range of applications, much emphasis has been placed on understanding the physicochemical behavior of polyelectrolyte/surfactant complexes, both at air-water interface and in the bulk. However, the correlation between the adsorption behavior and complexation in the bulk is less explored. In this research, this correlation is investigated and its dependence on polyelectrolyte concentration, molecular weight, charge localization and backbone rigidity and hydrophobicity is studied. The polyelectrolyte concentration is normalized with respect to it critical overlap concentration in order to compare the polymer in same concentration regime. Different polyelectrolyte systems were used to analyze the polyelectrolyte structural effect: …

Synthesis And Characterization Of Polyisobutylene-Block-Polyamides As Novel Thermoplastic Elastomers, Lauren Renee Kucera

Dissertations

Academic research has focused on two main areas of the living carbocationic polymerization (LCP) of isobutylene (IB): (1) the in-depth study and understanding of mechanistic features of the polymerization, and (2) the utilization and manipulation of the unique aspects of PIB in order to produce practically useful polymeric materials. The research included in this dissertation focuses mainly on the latter objective. This work details three main areas of research: (1) the copolymerization of PIB and polyamides (PA) to form novel thermoplastic elastsomers (TPEs), (2) the mechanical, physical and thermal properties of the novel PIB-PA materials, and (3) the use of …

Chemoenzymatic Synthesis Of An Analogue Of The Potent Antifungal Mycosubtilin, Mayank Srivastava

Master's Theses and Doctoral Dissertations

Mycosubtilin is a naturally occurring antifungal obtained from Bacillus subtilis that also displays limited antibiotic activity. Structurally, mycosubtilin is a macrocycliclipoheptapeptide of sequence Asn-Tyr-Asn-Gln-Pro-Ser-Asn, with the N-terminal Asn joined by a β-amino fatty acid. Besides the antifungal and antibiotic activities,these molecules are also hemolytic in nature. Hence, the purpose of this study is to synthesize a potent antifungal analogue of mycosubtilin, with a modified β-amino fatty acid, devoid of any hemolytic activity. A chemoenzymatic approach was used to synthesize the cyclic peptide, which involved the synthesis of the linear peptide chain of desired amino acid sequence, thiophenylderivatization of the peptide …

Characterization Of Short Chain Fatty Acids In Microbial Cultures By Dart-Ms And Gc-Ms, Shilpa Boppana

Master's Theses and Doctoral Dissertations

Colonic bacterial degradation of starch and other carbon sources produces short-chain fatty acids (SCFA) such as butyrate and lactate, which are important in human health and disease. Analysis of the results of mono- and co-cultures in in vitro systems has led to the conclusion that diverse microbial organisms may each contribute in part to the complete metabolism to produce SCFA. GC- MS and DART- MS were investigated as analytical tools in the present study to evaluate the production of butyrate and lactate in a test tube and bioreactor mono- and co-cultures. The overall research goal is to investigate biological model …

Investigation Of Storage-Phosphor Autoradiography For The Rapid Quantitative Screening Of Air Filters For Emergency Response Purposes, Athena Marie Gallardo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Past nuclear accidents, such as Chernobyl, resulted in a large release of radionuclides into the atmosphere. Radiological assessment of the vicinity of the site of the incident is vital to assess the exposure levels and dose received by the population and workers. Therefore, it is critical to thoroughly understand the situation and risks associated with a particular event in a timely manner in order to properly manage the event. Current atmospheric radiological assessments of alpha emitting radioisotopes include acquiring large quantities of air samples, chemical separation of radionuclides, sample mounting, counting through alpha spectrometry, and analysis of the data. The …

Ultrafast Dynamics And Two-Photon Absorption Properties Of Chromophores At Interfaces, Semere Ghebru Bairu

Dissertations

Materials with large two-photon absorption (2PA) cross-sections found applications in several areas such as sensor protection, 3D micro/nano fabrication, photodynamic therapy, optical data-storage, multi-photon sensing, multi-photon microscopy and imaging. Several successful research strategies were developed in literature to achieve 2PA materials with enhanced cross-sections. However, the obtained cross-sections are far from adequate and there is a need to develop new strategies. In a parallel development, numerous research efforts were focused on studying the dynamics of interfacial charge-transfer (ICT) across chromophoresemiconductor interfaces, especially in the context of dye-sensitized solar cells. While investigating the fundamentals of ICT, it was found that these …

Using Soil Organic Matter As An Iron Chelate To Enhance The Efficiency Of Modified Fenton Oxidition Of Diesel Fuel In Arctic Soils, Mary K. Sherwood

Masters Theses

Laboratory experiments were conducted to investigate the use of modified fenton chemistry on the treatment of three soils from the Canadian arctic, all with abundant soil organic matter, iron and manganese oxides, and diesel fuel contamination. The purpose of these studies was to (I) to assess modified fenton chemistry as a treatment option for petroleum-contaminated arctic soils, and (2) to evaluate the impact of soil organic matter on the modified fenton treatment of soils. Modified fenton treatment was compared for reactions in which ethylenediaminetetraacetate was added as a chelate vs. reactions in which the native soil organic matter was the …

Analyses Of Multivitamins In Nutraceuticals By Reverse Phase Hplc With Dad, Elsd And Ms, Hsiang-Chi Huang

All Theses

ABSTRACT
Vitamins are essential to human beings and support long-term healthy lifestyle. They exist widely in food, but in small amount. Hence, dietary supplements and fortified food products are more and more popular in the nutritional markets. According to the Infant Formula Act of 1980, the range of each of the nutrients should fall within a specific range or above the required minimum, so there is an increasing interest of accurate measurement of vitamins, particularly the B-group vitamins. However, traditional methods for vitamin B analyses are time-consuming and often in poor accuracy. As a result, rapid and reliable analytical methods …

Bond-Centric Modifications To Bond-Order Potentials And Ab-Initio Evaluation Of Nanostructured Materials Properties, Jaewoong Hur

All Dissertations

An improvement to the AIREBO potential for hydrocarbons is presented in which contribu-tions to the bond order are determined by the local bonding environment around the bond, rather than the average of the environments around the two constituent atoms. This bond-centric approach decreases the errors by ∼80% in the fullerene-type systems for which the original approach leads to the most severe errors. With the newly developed and parameterized method, energy errors are less than 0.7eV for a collection of hydrocarbon molecules not used in the fitting. This modified AIREBO potential is expected to be more useful not only for the …

Hydrothermal Chemistry, Crystal Structures, And Spectroscopy Of Novel Fluorides And Borates, Christopher Underwood

All Dissertations

This dissertation is a two-part manuscript highlighting the utilities of the hydrothermal method for exploring phase space, then extending that to the targeted growth of potentially useful materials. Chapters 3 - 5 discuss the synthesis of Group 4 fluorides and oxyfluorides. The study of this class of compounds in regards to their single crystal structures is a rich, but neglected area. Among the Group 4 metals, compounds based on Zr and Ti have been extensively studied, while those based on Th and Hf are sparsely reported and those based on Ce(IV) are nearly completely neglected. Using the hydrothermal method, many …

Hydrothermal Crystal Growth Of Metal Borates For Optical Applications, Carla Heyward

All Dissertations

Crystals are the heart of the development of advance technology. Their existence is the essential foundation in the electronic field and without it there would be little to no progress in a variety of industries including the military, medical, and technology fields. The discovery of a variety of new materials with unique properties has contributed significantly to the rapidly advancing solid state laser field. Progress in the crystal growth methods has allowed the growth of crystals once plagued by difficulties as well as the growth of materials that generate coherent light in spectral regions where efficient laser sources are unavailable. …

Synthesis Of Ester Derivatives Of Resveratrol As Potential Anti-Cancer Drugs, Parasmani Pageni

Electronic Theses and Dissertations

Resveratrol is a naturally occurring phytoalexin of the stilbene family produced by various plants in response to stress, UV radiation, and fungal attack. It is primarily found in peanuts, berries, grape skin, and red wine. Resveratrol has been found to exhibit anti-cancer, anti-inflammatory, anti-aging, and anti-oxidant properties. Research indicates that diets enriched with resveratrol containing substances result in less incidence of cancer. Unfortunately, the low bioavailability and solubility has been a huge setback for its potential prospects. As a result, efforts have been made to synthesize derivatives of resveratrol with increased solubility and bioavailability. Three triester novel resveratrol derivatives 3, …